The MQ-9 Gas Sensor Module is a 32mm x 20mm x 22mm semiconductor sensor detecting Carbon Monoxide, Methane, and LPG across a 200 to 10,000 ppm range, operating at 5V DC within -20°C to 40°C, and providing both 5V analog and 5V digital output simultaneously — unlike MQ-5 and MQ-6 which provide analog output only. The mq 9 sensor distinguishing feature is its dual-temperature heating cycle: the sensor alternates between a high-temperature phase that burns off surface contaminants and detects flammable gases like methane and LPG, and a low-temperature phase optimised for detecting carbon monoxide.
This dual-heating cycle is what makes the mq9 gas sensor uniquely capable of detecting CO — an odourless, colourless, and potentially lethal gas that other MQ-series sensors like MQ-5 and MQ-6 do not reliably detect. Per the mq 9 gas sensor datasheet, the heating cycle timing must be implemented in firmware — Arduino code alternates the heater drive between high and low voltage on a timed cycle, reading the sensor output during each phase for the corresponding gas type. The mq9 gas sensor module digital output provides a simple threshold alarm trigger alongside the analog concentration reading.
the dual-heating cycle adds firmware complexity compared to single-phase MQ sensors — this lpg gas detector and monoxide gas detector combination requires careful timing code for accurate dual-gas readings. Available from StemVolt, this MQ-9 gas sensor module is ideal for students and makers developing carbon monoxide, methane, and LPG detection systems, safety monitoring devices, and embedded gas sensing projects.
Related Products:
- Checkout The MQ-7 Gas Sensor Module
Features:
- Detects Carbon Monoxide, Methane, and LPG in single sensor
- Dual-temperature heating cycle separates CO detection from combustible gas
- Both analog and digital 5V outputs, unlike analog-only MQ-5/MQ-6
- 200-10000ppm range with -20°C to 40°C operating temperature
- Digital output provides simple threshold-based alarm trigger signal
Technical specifications:
 Applications
- Detects Carbon Monoxide, Methane, and LPG in single sensor
- Dual-temperature heating cycle separates CO detection from combustible gas
- Both analog and digital 5V outputs, unlike analog-only MQ-5/MQ-6
- 200-10000ppm range with -20°C to 40°C operating temperature
- Digital output provides simple threshold-based alarm trigger signal
Package includes:
- 1 x MQ-9 Gas Sensor Module
Varun Bajaj –
This product provides reliable detection of carbon monoxide, LPG, and combustible gases, making it suitable for robotics projects, safety systems, and educational applications
Shruti Nayak –
Highly recommended product
Gautham Kini –
Exactly as described
Archana Rao –
Delivered in 3 days with careful packaging, and helpful staff provided useful guidance for sensor integration and project development.